1. Field of the Invention
The present invention relates to a multi-purpose digital printer, and more particularly a printing machine with a transfer roller performing effectively textile-printing operations not only to the very thin and retractable printing materials, but also to the very thick and unfixed form or type of special materials.
2. Description of the Related Art
Generally, in the conventional printing machine utilizing a technique of subtractive mixture, a digital controller sends digitalized signals to a head of the printing machine, so that the head may inject proper amounts of ink of three primary colors comprising magenta, yellow, and cyan, and of a black color to a printing material to produce various color tones. Therefore, the latest printing machine makes it possible for a user to design more easily what she/he wants.
In the technique of subtractive mixture, the head of the printing machine equips several ink reservoirs, while each ink reservoir contains one color respectively. The head injects proper amounts of ink from each reservoir to produce a new color tone. The head often equips another ink reservoir containing special color to produce a new color tone, if necessary.
By referencing FIG. 1 and FIG. 2, the conventional printing machine will be described in the following statements.
The conventional printing machine equips a transfer belt 5 with a rail shape on the top of a base 3, while the base 3 is supported by both legs 1 contacting with the ground. A cartridge 9 is fixed with the transfer belt 5, so that a head 7 of the cartridge 9 can be moved through the transfer belt 5. Additionally, a transfer axis 50 is connected with a transfer motor (not shown) within a driving panel 18 included in the one side of the inner upper side of the base 3. Additionally, lots of transfer rollers 51 on the transfer axis 50 protrude from the top of the base 3 to make a printing material 17 move in the forward direction, while a press roller 40 placed correspondingly on the top of each transfer roller 51 presses down on the printing material 17.
Additionally, a feeding roller 11 included in the rear side of the digital printing machine supplies the printing material 17 to the top of the base 3. When the cartridge 9 moves reciprocally to the left or the right direction on the top of the printing material 17, the head 7 moving in combination with the cartridge 9 injects predetermined amounts of each color from the corresponding ink reservoir to perform printing operations. The printed material is then recoiled in a rewinding roller 12 located on the opposite side of the feeding roller 11.
An operation panel 16 covered by a cover 15 is equipped on the top of the base 3. Therefore, a user can input any desirable signal to be printed in the printing material 17.
However, the conventional printing machine described in the above statements has the following problems. After the printing material 17 is put between lots of transfer rollers 51 and press rollers 40, the transfer roller 51 rotates to make the printing material 17 move to the front side of the base 3. When the printing material 17 is extremely thin in the case of textile printing, the speed of the printing material 17 passing through between the transfer rollers 51 and the press rollers 40 is different from that of the printing material 17 before the transfer roller 51. Therefore, a portion of the printing material 17 is often wrinkled causing the printing colors to overlap, resulting in a higher percentage of defective printing operations, or is extended too much, causing the printing design to be distorted.